Gaseous electric discharge device



Oct. 31, 1939 A. RUTTENAUER GASEQUS ELECTRIC DISCHARGE DEVICE Filed Jan. 12, 1939 COATING 0F CADMIUM SILICA TE AND CALCIUM TUNGSTATE;

Inventor: Alfred Puttenauer;

Att orney Patented Oct. 1939 v a UNITED STATES PATENT OFFICE GASEOUS ELECTRIC DISCHARGE DEVICE Alfred Riittenauer, Berlin- Hal'ensee, Germany,

assignor to General Electric Company, a corporation of New York Application January 12, 1939, Serial No. 250,648 In Germany February 2, 1938 6 Claims. (Cl. 176122) My invention relates to gaseous electric disjacket is provide with a yellow lacquer or dye charge devices generally, and more particularly to or glass top-layer or base-layer, the filtering of such devices provided with a layer of luminesthe green and blue mercury rays will give a. cent material which is excited to luminescence golden-yellow light, even when a lower current by the electrical discharge. density than 100 ma. per sq. cm. is used. The 6 In the German patent, No. 646,716, an electric reason for this is that at lower current densities discharge tube or luminous tube with mercurythe luminescent radiation which contains much vapor filling has been described, which is interred manifests itself more pronouncedly than the nally provided with a luminophor or luminescent mercury radiation.

10 layer consisting of a cadmium silicate activated For a further understanding of the invention, 10 by means .of manganese, the current density of reference may be had to the drawing which is an the discharge ranging between 100 and 500 ma. elevation of one type of lamp in which my invenper sq. cm. Inasmuch as the cadmium silicate tlon may be employed. does not adhere well to the glass wall of the lamp The lamp illustrated in the drawing comprises or tube envelope, even when a binder layer of a tubular glass container or envelope l0 havin phosphoric acid has'been applied previously on sealed intoeach end thereof an electrode H which the glass wall, it was necessary in practice up to may be a thermionic cathode or a cold cathode the present to add to the cadmium silicate to as is well known in the. art. The envelope In 35 per cent of zinc oxide, which constitutes a containsa gaseousatmosphere which emits ultra- 20 sintering medium acting as cement. Inasmuch vi l t, radiations upon s a of a, discharge 0 as zinc oxide does not luminesce, this practice therethrough, preferably an atmosphere of merentails a loss in light. cury vapor together with a low pressure of a gas This loss in luminosity is avoided if, according such as argon. Preferably the inner surface of to the present invention, there is added to the the envelope I0 is coated with a layer l2 of mancadmium silicate which has been activated by ganese-activated cadmium silicate and samari- 25 means of manganese, a calcium tungstate which um-activated calcium tungstate in accordance has been activated by means of Samarium. The with my invention. With a current density of quantity of samarium which is introducedinto between 100 and 500 ma. per sq. cm. in the disthe calcium tungstate as activator may amount to charge, the lamp will emit light of approximately about t0 1 P r Ce The calcium tungstate daylight hue. However, a golden-yellow light 30 which has been activated by means of samariuin, may be obtained by the use of a yellow filter, and which is added to the cadmium silicate, acts hi h may b provided by making the envelope t y imila y o Zinc oxide as a sintering I 0 of yellow glass, or by surrounding a clear enmedium for the cadmium silicate, but it acts also ve1ope m t a yellow glass j k t r t b r as a source of illumination since the mercury by providing the envelope ID or a .clear glass 35 radiation stimulates its luminescence. As a rejacket ith a layer of yellow lacquer. suit, the total light output of the discharge lamp Wh t I claim as new and desire to secure by -or luminous tube is increased. A special advan- Lett r Patent of the United States:

tage liesln the fact that h luminescent light 1. A gaseous electric discharge lamp device 40 of the calcium tungstate activated by means of comprising a container, a gaseous atmosphere 40 samarium has an orange color, just as that of in said container capable of emitting ultra-viocadmium silicate. Because of this, the hue of the let radiations upon passage of an electrical distotal .radiation made up of the mercury radiation charge therethrough and a coating of luminesand luminescent radiation will not be changed. cent material in said container consisting of man- If the discharge lamp or luminous tube is ganese-activated cadmium silicate and samari- 4 equipped, in the usual manner, with a clear glass -um-activated calcium tungstate. envelope, the following result is obtained: With a 2. A gaseo s e e dis f p device current density of the discharge ranging between comprising a container, a gaseous atmosphere in 100 and 500 ma. per sq. cm., the mixture of the said container capable of emitting ultra-violet orange-hued luminescent radiation with the blueradiations upon passage of an electrical discharge 50 green mercury radiation will give a total radiatherethrough and a coating of luminescent mation of approximately daylight aspect. However, terial in said container consisting of manganeseif a lamp envelope consisting of yellow glass is activated cadmium silicate and about 20 to 35 used, or a yellow-glass jacket which surrounds per cent of samarium-activat'ed calcium tungthe lamp envelope, or it the lamp envelope or the state.

3. A gaseous electric discharge lamp device comprising a container, a yellow filter associated with said container, a gaseous atmosphere in said container capable of emitting ultra-violet radiations upon passage of an electrical discharge therethrough and a coating of luminescent material in said container consisting of manganeseactivated cadmium silicate and samarium-actlvated calcium tungstate.

4. A gaseous electric discharge lamp device comprising a container, a gaseous atmosphere in said container comprising mercury vapor capable of emitting ultra-violet radiations upon passage of an electrical discharge therethrough and a coating of luminescent material in said container consisting of manganese-activated cadmium silicate and Samarium-activated calcium tungstate.

5. A gaseous electric discharge lamp device anaaac comprising a container, a gaseous atmosphere in said container comprising mercury vapor capable of emitting ultra-violet radiations upon passage of an electrical discharge therethrough and a coating of luminescent material in said container consisting of manganese-activated cadmium silicate and about 20 to 35 per cent of Samariumactivated calcium tungstate.

6. A gaseous electric discharge lamp device comprising a, container, a yellow filter associated with said container, a gaseous atmosphere in said continer comprising mercury vapor capable of emitting ultra-violet radiations upon passage of an electrical discharge therethrough and a coating of luminescent material in said container consisting of manganese-activated cadmium silicate and samarium-activated calcium tungstate.

ALFRED RT'L'T'I'IENAUER. 

